Press for producing fine cut parts

ABSTRACT

A press for producing fine cut parts includes a tool holder, a cross-beam and a tool having a plurality of tool parts, wherein the tool includes a tool block. The tool holder includes a set of transmission devices. The cross-beam is drivingly connected, via the set of transmission devices, to at least some of the tool parts required to produce a fine cut part and arranged in the tool block. The cross-beam is actuated by at least two cross-beam drives.

The invention relates to a press for producing fine cut parts.

BACKGROUND OF THE INVENTION

The manufacturing method for producing fine cut parts and also the presses used in this connection are generally known in the prior art.

Cut parts of extremely high quality and with very low tolerances can be produced by means of fine cutting. In order for the plastic deformation process to be performed in a controlled manner and to ensure that desired [sic] changes such as cracks do not occur in the material structure, tools having a plurality of tool parts are used for fine cutting. These tool parts each have particular functions and are individually actuated via drives in order to apply the corresponding cutting forces, knife-edge ring forces and counter-holding forces.

The disadvantages of the presses in the prior art are that these have a severely limited number of strokes depending upon the workpiece and the installation space of the tool parts is limited to a press table size of about 1.1 m×1.1 m. Presses are known in which a plurality of tools are used jointly on one press table. However, this is only possible with a considerable additional outlay owing to the central arrangement of the pad axes in the press table. However, irrespective of the number of tools used, a multiplicity of drives are required in order to actuate the individual tool parts.

The object of the invention is to provide a press for producing fine cut parts having a larger usable press table size and a reduced number of drives required to actuate the tools, and thus to provide a more cost-effective and more flexible press.

BRIEF DESCRIPTION OF THE INVENTION

To achieve this object, a press for producing fine cut parts is provided, having a tool holder, a cross-beam and a tool having a plurality of tool parts, wherein the tool comprises a tool block. The tool holder comprises a set of transmission means, wherein the cross-beam is drivingly connected, via the set of transmission means, to at least some of the tool parts required to produce a fine cut part and arranged in the tool block, and wherein the cross-beam is actuated by at least two cross-beam drives.

In terms of the invention, a tool part is a part of a tool which has a particular function, in particular limited to an area, and/or can be actuated independently of other parts of the tool. Since a plurality of tool parts are operated via a cross-beam, the number of drives required for actuating the tool parts can be reduced to a few cross-beam drives actuating the common cross-beam. The cross-beam can be designed to be bending resistant, whereby the actuation of tool parts is possible over a length of considerably more than 1 m, whereby considerably larger press table sizes can be provided.

The press can comprise a second tool holder and a second cross-beam, and the tool can comprise a second tool block, wherein the second tool holder comprises a second set of transmission means, wherein the second cross-beam is drivingly connected, via the second set of transmission means, to at least some of the tool parts required to produce a fine cut part and arranged in the second tool block, and wherein the second cross-beam is actuated by at least two cross-beam drives. This design having the second tool holder, which is arranged in particular opposite the first tool holder, and the second cross-beam means that the number of drives required to actuate the tool parts can be further reduced.

In accordance with an advantageous embodiment, the first cross-beam is drivingly connected, via the first set of transmission means, to all the tool parts arranged in the first tool block which apply a knife-edge ring force and/or a counter-holding force to a workpiece, and/or the second cross-beam is drivingly connected, via the second set of transmission means, to all the tool parts arranged in the second tool block which apply a knife-edge ring force and/or a counter-holding force to a workpiece. This has the advantage that all the tool parts which apply a knife-edge ring force and/or a counter-holding force to a workpiece can be actuated jointly by the cross-beam allocated to each of them, and can be pressurised, and therefore less drives are required to actuate the tool parts.

In accordance with a further advantageous embodiment, the first cross-beam is drivingly connected, via the first set of transmission means, to all the tool parts required to produce a fine cut part and arranged in the first tool block and/or the second cross-beam is drivingly connected, via the second set of transmission means, to all the tool parts required to produce a fine cut part and arranged in the second tool block. In this manner, all the tool parts can be actuated jointly by the cross-beam allocated thereto in each case, and can be pressurised, whereby the required number of drives for actuating the tool parts is minimised.

It is advantageous if each tool part required to produce a fine cut part is drivingly connected to a transmission means in each case. The transmission means can hereby be adapted to the tool part and the function thereof and e.g. can have a particular length in order to exert its function at a particular time.

Preferably, the transmission means are pressure pins because these permit direct and efficient force transmission, have a long service life and are cost-effective.

The first and/or second tool holder comprises e.g. a plurality of receivers for pressure pins, wherein in particular more receivers are provided than are necessary for producing a fine cut part. In this manner, the pressure pins can be arranged corresponding to the requirements of different tools, whereby the press is provided for a multiplicity of different tools and can be used in a flexible manner.

Preferably, each cross-beam is actuated by at least two and preferably no more than three cross-beam drives. Reducing the number of cross-beam drives to merely two or three cross-beam drives in each case is a further optimisation in terms of efficiency and costs.

In an advantageous embodiment, the cross-beam drives of the first cross-beam and/or the cross-beam drives of the second cross-beam are each mutually force-controlled. In this manner, each cross-beam forms a hydraulic balance, whereby each cross-beam exerts a homogeneous pressure onto the transmission means over its surface.

In a further advantageous embodiment, the cross-beam drives of the first cross-beam and/or the cross-beam drives of the second cross-beam are each driven by a single drive unit. Since a plurality of cross-beam drives are driven jointly by a drive unit, the number of required drive units is reduced, which reduces the costs of producing the press.

Preferably, the cross-beam, drives of the first cross-beam and the cross-beam drives of the second cross-beam are driven by a single drive unit. Since all the cross-beam drives are driven jointly by only one drive unit, the number of required drive units is minimised, and the costs of the press are further reduced.

The press is e.g. a servo-driven toggle press which comprises in particular a 2-toggle system operated by at least one drive unit.

In accordance with an advantageous embodiment, the press has a maximum pressing force of 1500 kN, preferably 1100 kN and/or a press table length of up to 4.0 m, preferably of up to 3.5 m. This embodiment offers a particularly good cost-value ratio and permits a high number of strokes and a good cutting output and parts production.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and features will be apparent from the following description in conjunction with the attached drawings, in which:

FIG. 1 shows a broken away sectional view of a section of a press in accordance with the invention in an open press position,

FIG. 2 shows a broken away sectional view of the section of the press from FIG. 1 in a press position with a tool attached, and

FIG. 3 shows a broken away sectional view of the section of the press from FIG. 1 in a closed press position.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a press 10 in the open position, having a first tool holder 12, which is designed as a press table in one piece with a machine frame 13, and a second tool holder 14 which is designed as a press plunger and is mounted in the machine frame 13 by means of a bearing device 15.

A tool 16 having a lower first tool block 18 and an upper second tool block 20 is arranged between the first and second tool holders 12, 14, said tool blocks having a plurality of tool parts 22. A workpiece 23 is arranged between the first and second tool blocks 18, 20.

The first tool holder 12 comprises a first cross-beam 24 and a first set 26 of transmission means 28, via which the first cross-beam 24 is drivingly connected to some of the tool parts 22 in the first tool block 18 which are required for producing a fine cut part.

The second tool holder 14 comprises a second cross-beam 30 and a second set 32 of transmission means 28, via which the second cross-beam 30 is drivingly connected to some of the tool parts 22 in the second tool block 20 which are required for producing a fine cut part.

The transmission means 28 are designed as pressure pins which are arranged in corresponding receivers 34 in the corresponding tool holders 12, 14.

The pressure pins can be produced from steel.

Each tool part 22 can be drivingly connected by means of its own transmission means 28. Alternatively, tool parts 22 can also be drivingly connected by means of a plurality of transmission means 28.

In an alternative embodiment, not illustrated, the tool holders 12, 14 comprise a multiplicity of receivers 34 for pressure pins. In this case, more receivers 34 are provided than are required for actuating the tool parts 22 in order to produce a particular fine cut part. The receivers 34 are arranged such that different tools 16 having differently arranged tool parts 22 can be used in the press 10 by correspondingly equipping the receivers 34 with pressure pins for producing fine cut parts.

In a further alternative embodiment, not illustrated, a fluid, e.g. hydraulic fluid, is used as the transmission means 28, said fluid being pressurised by the respective cross-beams 24, 30. In this case, differentiated actuation of individual tool parts 22 is possible only with additional outlay. Furthermore, all the areas of the press 10 in contact with the fluid must be sealed.

The first cross-beam 24 is arranged on the lower side of the first tool holder 12 opposite the tool 16 and is mounted on the first tool holder 12 by means of a cross-beam bearing 35, wherein the first cross-beam 24, in the section of the press 10 which is not illustrated, is mounted on the first tool holder 12 preferably analogously to the illustrated cross-beam bearing 35 by means of at least one further cross-beam bearing 35.

The first cross-beam 24 is further actuated by two mutually force-controlled cross-beam drives 36, wherein the second cross-beam drive 36 is arranged in the section of the press 10 which is not illustrated, preferably analogously to the illustrated cross-beam drive 36.

The second cross-beam 30 is arranged on the upper side of the second tool holder 14 opposite the tool 16 and is mounted on the second tool holder 14 by means of a cross-beam bearing 35, wherein the second cross-beam 30, in the section of the press 10 which is not illustrated, is mounted on the second tool holder 14 preferably analogously to the illustrated cross-beam bearing 35 by means of at least one further cross-beam bearing 35.

The second cross-beam 30 is further actuated by two mutually force-controlled cross-beam drives 37, wherein the second cross-beam drive 37 is arranged in the section of the press 10 which is not illustrated, preferably analogously to the illustrated cross-beam drive 37.

The cross-beam drives 36, 37 are each drivingly connected to the corresponding cross-beams 24, 30 in each case in end sections 38, 39 thereof.

In their end sections 38, 39 adjoining the cross-beam bearing 35, the cross-beams 24, 30 have a smaller thickness in relation to the illustrated sectional plane than in a correspondingly intermediate section 40, 41.

The cross-beams 24, 30 can each also be drivingly connected to a further third cross-beam drive 36, 37 which is arranged in each case preferably at a location between the two corresponding cross-beam drives 36, 37.

The section of the cross-beams 24, 30 against which a third cross-beam drive 36, 37 lies can have a smaller thickness in relation to the illustrated sectional plane than in a section 40, 41 of the cross-beams 24, 30 correspondingly located between the cross-beam drives 36, 37.

The first cross-beam 24 and/or the second cross-beam 30 is/are designed to be bending resistant.

The first cross-beam 24 and/or the second cross-beam 30 extend(s) in each case over all the receivers 34 of the corresponding tool holder 12, 14 so that the respective cross-beam 24, 30 is drivingly connected to the corresponding transmission means 28 in each receiver 34 of its tool holder 12, 14.

By virtue of the fact that the cross-beams 24. 30 extend continuously over the entire extent of the tool holder 12, 14, it becomes possible to arrange receivers 34 over the entire extent of the tool holder 12, 14 and to drive transmission means 28 provided in the receivers 34, whereby the press 10 is suitable for a multiplicity of different tools 16, in particular for producing fine cut parts.

The cross-beams 24, 30 are drivingly connected, by means of the transmission means 28, only to some of the tool parts 22 required to produce a fine cut part. For example, some of the tool parts 22 arranged in the second tool block 20 are drivingly connected only to the second tool holder 14 and not additionally to the cross-beam 30.

In an alternative embodiment, one of the two cross-beams 24, 30 or the two cross-beams is/are drivingly connected, via the corresponding set 26, 32 of transmission means 28, to all the tool parts 22 arranged in the corresponding tool block 18, 20 which apply a knife-edge ring force and/or a counter-holding force to the workpiece 23.

In a further alternative embodiment, one cross-beam 24, 30 or the two cross-beams 24, 30 is/are drivingly connected, via the corresponding set 26, 32 of transmission means 28, to all the tool parts 22 arranged in the corresponding tool block 18, 20 which are required to produce a fine cut part.

The cross-beam drives 36, 37 are driven jointly by an individual drive unit 42.

Alternatively, the cross-beam drives 36 of the first cross-beam 24 can be driven jointly by an individual drive unit 42 and/or the cross-beam drives 37 of the second cross-beam 30 can be driven jointly by a further individual drive unit 42.

The drive unit 42 can be a hydraulic pump.

The press 10 can be a servo-driven toggle press, in a particularly rigid design with a 2-toggle system, which is operated by at least one drive unit 42.

The press 10 can have a maximum pressing force of 1500 kN, preferably of 1100 kN.

The press 10 can have a press table length of up to 4.0 m, preferably of up to 3.5 m.

In order to produce a fine cut part, the workpiece 23 is introduced into the press 10, when the press 10 is in the open position, between the first and second tool blocks 18, 20, and at that location rests against the first tool block 18.

In the next step, as shown in FIG. 2, the second tool block 20 is placed from above onto the side of the workpiece 23 opposite the first tool block 18, by the second tool holder 14 being lowered in the machine frame 13.

In the subsequent step, illustrated in FIG. 3, the first and second cross-beams 24, 30 are each moved via the corresponding cross-beam drives 36, 37 from a first position into a second position. The transmission means 28 move the corresponding tool parts 22 drivingly connected thereto and/or pressurise same in order to apply a knife-edge ring force, a counter-holding force and/or a cutting force to the workpiece 23 depending upon the function of the corresponding tool part 22. The workpiece 23 is held in position by the knife-edge ring force. The tool parts 22 which are provided for cutting apply a force to the workpiece 23 which results in separation of the workpiece 23 at the cutting edges 44 formed by individual passes of different tool parts 22, whereas the counter-holding forces prevent undesired deformation of the workpiece 23 and thus a controlled cut is ensured. This ensures that the produced fine cut parts are of high quality and have low tolerances.

The press 10 in accordance with the invention thus represents a pressing concept which is particularly cost-effective and produces high quality fine cut parts owing to the tool parts 22 driven via common cross-beams 24, 30 as well as the few cross-beam drives 36, 37 required for this purpose. 

1. A press for producing fine cut parts, having a tool holder, a cross-beam and a tool having a plurality of tool parts, wherein the tool comprises a tool block, wherein the tool holder comprises a set of transmission devices, wherein the cross-beam is drivingly connected, via the set of transmission devices, to at least some of the tool parts required to produce a fine cut part and arranged in the tool block, and wherein the cross-beam is actuated by at least two cross-beam drives.
 2. The press as claimed in claim 1 wherein the press comprises a second tool holder and a second cross-beam, and in that the tool comprises a second tool block, wherein the second tool holder comprises a second set of transmission devices, wherein the second cross-beam is drivingly connected, via the second set of transmission devices, to at least some of the tool parts required to produce a fine cut part and arranged in the second tool block, and wherein the second cross-beam is actuated by at least two cross-beam drives.
 3. The press of claim 1 wherein the first cross-beam is drivingly connected, via the first set of transmission devices, to all the tool parts arranged in the first tool block which apply a knife-edge ring force and/or a counter-holding force to a workpiece and/or the second cross-beam is drivingly connected, via the second set of transmission devices, to all the tool parts arranged in the second tool block which apply a knife-edge ring force and/or a counter-holding force to a workpiece.
 4. The press of claim 1 wherein the first cross-beam is drivingly connected, via the first set of transmission devices, to all the tool parts required to produce a fine cut part and arranged in the first tool block, and/or the second cross-beam is drivingly connected, via the second set of transmission devices, to all the tool parts required to produce a fine cut part and arranged in the second tool block.
 5. The press of claim 1 wherein each tool part required to produce a fine cut part is drivingly connected to a transmission devices in each case.
 6. The press of claim 1 wherein the transmission devices are pressure pins.
 7. The press of claim 6 wherein the first and/or second tool holder comprises a plurality of receivers for pressure pins, in particular wherein more receivers are provided than are necessary for producing a fine cut part.
 8. The press of claim 1 wherein each cross-beam is actuated by at least two and preferably no more than three cross-beam drives.
 9. The press of claim 1 wherein the cross-beam drives of the first cross-beam and/or the cross-beam drives of the second cross-beam are each mutually force-controlled.
 10. The press of claim 1 wherein the cross-beam drives of the first cross-beam and/or the cross-beam drives of the second cross-beam are each driven by a single drive unit.
 11. The press of claim 1 wherein the cross-beam drives of the first cross-beam and the cross-beam drives of the second cross-beam are driven by a single drive unit.
 12. The press of claim 1 wherein the press is a servo-driven toggle press which comprises in particular a 2-toggle system operated by at least one drive unit.
 13. The press of claim 1 wherein the press has a maximum pressing force of 1500 kN, and/or a press table length of up to 4.0 m.
 14. The press of claim 13 wherein the press has a maximum pressing force of 1100 kN and/or a press table length of up to 3.5 m. 